Remove bind_email and bind_msisdn (#5964)

Removes the `bind_email` and `bind_msisdn` parameters from the `/register` C/S API endpoint as per [MSC2140: Terms of Service for ISes and IMs](https://github.com/matrix-org/matrix-doc/pull/2140/files#diff-c03a26de5ac40fb532de19cb7fc2aaf7R107).

4 files changed, 10 insertions, 64 deletions

diff --git a/changelog.d/5964.feature b/changelog.d/5964.feature
new file mode 100644
index 0000000000..273c9df026
--- /dev/null
+++ b/changelog.d/5964.feature
@@ -0,0 +1 @@
+Remove `bind_email` and `bind_msisdn` parameters from /register ala MSC2140.
\ No newline at end of file
diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index e59b2a3684..975da57ffd 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -543,9 +543,7 @@ class RegistrationHandler(BaseHandler):
         return (device_id, access_token)
 
     @defer.inlineCallbacks
-    def post_registration_actions(
-        self, user_id, auth_result, access_token, bind_email, bind_msisdn
-    ):
+    def post_registration_actions(self, user_id, auth_result, access_token):
         """A user has completed registration
 
         Args:
@@ -554,18 +552,10 @@ class RegistrationHandler(BaseHandler):
                 registered user.
             access_token (str|None): The access token of the newly logged in
                 device, or None if `inhibit_login` enabled.
-            bind_email (bool): Whether to bind the email with the identity
-                server.
-            bind_msisdn (bool): Whether to bind the msisdn with the identity
-                server.
         """
         if self.hs.config.worker_app:
             yield self._post_registration_client(
-                user_id=user_id,
-                auth_result=auth_result,
-                access_token=access_token,
-                bind_email=bind_email,
-                bind_msisdn=bind_msisdn,
+                user_id=user_id, auth_result=auth_result, access_token=access_token
             )
             return
 
@@ -578,13 +568,11 @@ class RegistrationHandler(BaseHandler):
             ):
                 yield self.store.upsert_monthly_active_user(user_id)
 
-            yield self._register_email_threepid(
-                user_id, threepid, access_token, bind_email
-            )
+            yield self._register_email_threepid(user_id, threepid, access_token)
 
         if auth_result and LoginType.MSISDN in auth_result:
             threepid = auth_result[LoginType.MSISDN]
-            yield self._register_msisdn_threepid(user_id, threepid, bind_msisdn)
+            yield self._register_msisdn_threepid(user_id, threepid)
 
         if auth_result and LoginType.TERMS in auth_result:
             yield self._on_user_consented(user_id, self.hs.config.user_consent_version)
@@ -603,14 +591,12 @@ class RegistrationHandler(BaseHandler):
         yield self.post_consent_actions(user_id)
 
     @defer.inlineCallbacks
-    def _register_email_threepid(self, user_id, threepid, token, bind_email):
+    def _register_email_threepid(self, user_id, threepid, token):
         """Add an email address as a 3pid identifier
 
         Also adds an email pusher for the email address, if configured in the
         HS config
 
-        Also optionally binds emails to the given user_id on the identity server
-
         Must be called on master.
 
         Args:
@@ -618,8 +604,6 @@ class RegistrationHandler(BaseHandler):
             threepid (object): m.login.email.identity auth response
             token (str|None): access_token for the user, or None if not logged
                 in.
-            bind_email (bool): true if the client requested the email to be
-                bound at the identity server
         Returns:
             defer.Deferred:
         """
@@ -661,28 +645,15 @@ class RegistrationHandler(BaseHandler):
                 data={},
             )
 
-        if bind_email:
-            logger.info("bind_email specified: binding")
-            logger.debug("Binding emails %s to %s" % (threepid, user_id))
-            yield self.identity_handler.bind_threepid(
-                threepid["threepid_creds"], user_id
-            )
-        else:
-            logger.info("bind_email not specified: not binding email")
-
     @defer.inlineCallbacks
-    def _register_msisdn_threepid(self, user_id, threepid, bind_msisdn):
+    def _register_msisdn_threepid(self, user_id, threepid):
         """Add a phone number as a 3pid identifier
 
-        Also optionally binds msisdn to the given user_id on the identity server
-
         Must be called on master.
 
         Args:
             user_id (str): id of user
             threepid (object): m.login.msisdn auth response
-            bind_msisdn (bool): true if the client requested the msisdn to be
-                bound at the identity server
         Returns:
             defer.Deferred:
         """
@@ -698,12 +669,3 @@ class RegistrationHandler(BaseHandler):
         yield self._auth_handler.add_threepid(
             user_id, threepid["medium"], threepid["address"], threepid["validated_at"]
         )
-
-        if bind_msisdn:
-            logger.info("bind_msisdn specified: binding")
-            logger.debug("Binding msisdn %s to %s", threepid, user_id)
-            yield self.identity_handler.bind_threepid(
-                threepid["threepid_creds"], user_id
-            )
-        else:
-            logger.info("bind_msisdn not specified: not binding msisdn")
diff --git a/synapse/replication/http/register.py b/synapse/replication/http/register.py
index 87fe2dd9b0..38260256cf 100644
--- a/synapse/replication/http/register.py
+++ b/synapse/replication/http/register.py
@@ -106,7 +106,7 @@ class ReplicationPostRegisterActionsServlet(ReplicationEndpoint):
         self.registration_handler = hs.get_registration_handler()
 
     @staticmethod
-    def _serialize_payload(user_id, auth_result, access_token, bind_email, bind_msisdn):
+    def _serialize_payload(user_id, auth_result, access_token):
         """
         Args:
             user_id (str): The user ID that consented
@@ -114,17 +114,8 @@ class ReplicationPostRegisterActionsServlet(ReplicationEndpoint):
                 registered user.
             access_token (str|None): The access token of the newly logged in
                 device, or None if `inhibit_login` enabled.
-            bind_email (bool): Whether to bind the email with the identity
-                server
-            bind_msisdn (bool): Whether to bind the msisdn with the identity
-                server
         """
-        return {
-            "auth_result": auth_result,
-            "access_token": access_token,
-            "bind_email": bind_email,
-            "bind_msisdn": bind_msisdn,
-        }
+        return {"auth_result": auth_result, "access_token": access_token}
 
     @defer.inlineCallbacks
     def _handle_request(self, request, user_id):
@@ -132,15 +123,9 @@ class ReplicationPostRegisterActionsServlet(ReplicationEndpoint):
 
         auth_result = content["auth_result"]
         access_token = content["access_token"]
-        bind_email = content["bind_email"]
-        bind_msisdn = content["bind_msisdn"]
 
         yield self.registration_handler.post_registration_actions(
-            user_id=user_id,
-            auth_result=auth_result,
-            access_token=access_token,
-            bind_email=bind_email,
-            bind_msisdn=bind_msisdn,
+            user_id=user_id, auth_result=auth_result, access_token=access_token
         )
 
         return 200, {}
diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py
index 107854c669..1ccd2bed2f 100644
--- a/synapse/rest/client/v2_alpha/register.py
+++ b/synapse/rest/client/v2_alpha/register.py
@@ -481,8 +481,6 @@ class RegisterRestServlet(RestServlet):
                 user_id=registered_user_id,
                 auth_result=auth_result,
                 access_token=return_dict.get("access_token"),
-                bind_email=params.get("bind_email"),
-                bind_msisdn=params.get("bind_msisdn"),
             )
 
         return 200, return_dict